1. Field of the Invention
The present invention relates to a converged IP messaging (CPM) service.
2. Description of the Related Art
These days, various services, for example, an SMS, an MMS, an e-mail service, and the like, allow for transmission and reception of messages via mobile devices.
Recently, there have been attempts to integrate those services, which are separately provided to transmit and receive messages, and a CPM service is one of these attempts.
The CPM service is a service in which the user can send and receive a CPM message in the environments of an IP multimedia subsystem. The CPM supports the environments of a pager mode message and a session mode message. Furthermore, the CPM service supports not only discrete media but also continuous media.
FIG. 1 is a block diagram illustrating the configuration of a network and a terminal for CPM services.
Referring to FIG. 1, there are illustrated a terminal 10, a SIP/IP network 50, a message storage server 60, an interworking server 70, and a CPM server 80.
First, the terminal 10 may include a message storage client 11 and a CPM client 12. The message storage client 11 stores transmitted and received messages, and synchronizes the stored messages with the message storage server 60.
The SIP/IP network 50 may be a network on the basis of IMS.
The message storage server 60 receives a message from the CPM server 80, and serves to store transmitted and received messages and a conversation history with the media based on the user preference. Furthermore, the message storage server 60 may share data through synchronization with the terminal 10. In other words, the message storage server 60 receives and stores a message stored in the terminal 10, and transmits the message stored in the message storage server 60 to the terminal 10.
The message storage server 60 uses IMAO protocol for the synchronization. Accordingly, the message storage server 60 serves as an IMAP server, and the terminal 10 is operated as an IMAP client.
The interworking server 70 may include an interworking function unit 71 and an interworking selection function unit 72. The interworking function unit 71 serves to convert a CPM message into SMS, MMS, and the like, or convert SMS, MMS, and the like, into a CPM message. The interworking selection function unit 72 serves to determine whether or not the conversion is to be performed.
The CPM server 80 may include a CPM participating function (PF) server 81 and a CPM controlling function (CF) server 82. The CPM PF server 81 transmits a message to the message storage server 60. Also, the CPM PF server 81 transmits and/or receives messages to and/or from the CPM client 12 of the terminal 10.
FIG. 2 is an exemplary view illustrating a process of transmitting and/or receiving CPM messages.
Referring to FIG. 2, there are illustrated a terminal A1 10A of a user A, terminals B1 and B2 10B of a user B, a home network of the user A, a home network of the user B, and a message storage server 60. The home network of the user A may include a SIP/IP network 50A and a CPM PF server 81A. The home network of the user B may include a SIP/IP network 50B and a CPM PF server 81B.
First, according to a request of the user A, the terminal A1 10A transmits a message to the CPM PF server 81A through the SIP/IP network 50A (S01, S02). The CPM PF server 81A transmits the message to the CPM PF server 81B through the SIP/IP network 50A within a home network of the user A and the SIP/IP network 50B in a home network of the user B (S03, S04, S05).
When receiving the message, the CPM PF server 81B transmits it to a terminal B1 10B of the user B though the SIP/IP network 50B (S06, S07).
Also, when receiving the message, the CPM PF server 81B transmits it to a terminal B2 10B of the user B though the SIP/IP network 50B (S08, S09).
The terminals B1 10B and B2 10B of the user B transmit OK messages respectively to the CPM PF server 81B through the SIP/IP network 50B within a home network of the user B (S10, S11).
When receiving the OK message, the CPM PF server 81B transmits it to the CPM PF server 81A of the user A through the SIP/IP network 50B within the home network of the user B and the SIP/IP network 50A within the home network of the user A (S12 to S15).
When receiving the OK message, the CPM PF server 81A within the home network of the user A delivers the OK message to the terminal A1 10A that has transmitted the message (S16).
In the above, there has been described a process of delivering a message. Hereinafter, an example will be illustrated in which the transmitted and received message is stored in the message storage server 60.
FIG. 3 is a flow chart illustrating an operation of a message storage server of FIG. 1 and a message synchronization process.
The processes S21-S25 illustrated in FIG. 3 are similar to the processes S01-S05 illustrated in FIG. 2, and thus the content of FIG. 1 will be used for the description.
When the CPM PF server 81B receives a CPM message from the terminal A1, the CPM PF server 81B determines whether to store it in the message storage server 60 and deliver it based on subscriber information of the user B (S26).
When the CPM message is determined to be stored and delivered, the CPM PF server 81B transmits the CPM message to the message storage server 60 (S27).
The message storage server 60 stores the received CPM message (S28), and transmits an OK message to the CPM PF server 81B (S29). In this case, it is assumed that first and second messages have been stored in the message storage server 60 and have been previously synchronized with the terminal B1 10B. An identification indicating that the received CPM message has not been synchronized with the terminal B1 10B is stored in the message storage server 60.
The CPM PF server 81B transmits the CPM message to the terminal B1 10B via the SIP/IP network 50B (S30).
Upon receiving the CPM message, the terminal B1 stores the CPM message in the message storage client (S31). In this case, it is assumed that first and second messages have been stored in the terminal B1 10B and have been previously synchronized with the message storage server 60. An identification indicating that the received CPM message has not been synchronized with the message storage server 60 is stored in terminal B1 10B.
The terminal B1 10B transmits an OK message to the CPM PF server 81B via the SIP/IP network 81B within the home network of the user B (S32).
When the CPM PF server 81B receives the OK message, it transmits the received OK message to the CPM PF server 81A of the user A via the SIP/IP network 50B within the home network of the user B and the SIP/IP network 50A within the home network of the user A (S33 to S35).
When the CPM PF server 81A within the home network of the user A receives the OK message, it delivers the OK message to the terminal A1 10A which had transmitted the CPM message (S36).
Meanwhile, in order to be synchronized with the message storage server 60, the terminal B1 (10B) transmits a synchronization request message to the message storage server 60 (S37).
Then, the message storage server 60 checks whether or not there is a message which has not been synchronized with the terminal B1 10B. If it is checked that the newly stored CPM message has not been synchronized by the identification, the message storage server 60 notifies the terminal B1 10B about the presence of the new message (S38).
Upon checking the presence of the non-received message based on the notification, the terminal B1 10B requests the non-received message from the message storage server 60 (S40).
The message storage server 60 transmits the CPM message to the terminal B1 10B (S41). However, the CPM message has been already received by the terminal B1 10B in step S30, resulting in that the terminal B1 10B repeatedly receives the same CPM message again.
Meanwhile, if it is checked by the identification that the stored message is not synchronized yet in step S31, the terminal B1 10B determines that there is a non-transmitted message (S42), and transmits the CPM message to the message storage server 60 (S43).
In this case, however, the CPM message has been already received by the message storage server 60 in step S27, resulting in that the message storage server 60 repeatedly receives the same CPM message again.
As described above, the message storage server 60 provides the function of storing the transmitted or received message and message synchronization function, but it has a technical problem in that the same message is repeatedly delivered and stored.
Also, because the same message is repeatedly transmitted and received, the network resource is wasted. In general, it is known that a single user usually sends or receives 10 or some messages in average a day. Thus, if one hundred users are within the network, the waste of the network resources due to the repeatedly transmitted and received messages would become severe.
In addition, generally, the terminal 10 is a portable device with a limited memory size, so the repeated storing of the messages would cause a waste of the memory. In particular, it is known that a single user usually sends or receives 10 or some messages in average a day. Thus, the repeated storing of the messages would end in storing of multiple unnecessary messages, accelerating the shortage of storage space, and making the user to frequently erase the messages.